1. Field of the Invention
The present invention relates to an apparatus and method for sensing the position of an object by propagating electromagnetic radiation in a space, and particularly to an apparatus and method for sensing the position of an object by propagating terahertz (THz) electromagnetic radiation in a space.
2. Description of the Related Background Art
In this specification, the terminology “the terahertz (THz) electromagnetic radiation” or “terahertz (THz) radiation” or “terahertz (THz)” is used for radiation in a frequency range between about 30 GHz and about 30 THz. Conventionally, terahertz (THz) radiation pulses are used for position sensing using terahertz (THz) radiation, as disclosed in “Time domain terahertz impulse ranging studies (Applied Physics Letters, Vol. 67, p. 1960, 1995)”. A femtosecond laser used for generation of the terahertz (THz) radiation pulses is, however, typically expensive and large in size.
Accordingly, a relatively low-cost position sensing apparatus is strongly desired.